Gelhardt cited “family considerations” for his departure in his resignation letter to his boss, Maj. Gen. Thomas Carden.

“Please accept this email as my letter of resignation,” he wrote to Carden, the state’s adjutant general. “Let’s coordinate an appropriate time/location to hand over the command to the next volunteer to take the GSDF to the next level.”

“We appreciate Mark Gelhardt’s volunteerism,” Carden told the AJC. “He has resigned his volunteer position to spend more time with his family, and we wish him all the best.”

Gelhardt had a long history in the military before his retirement. He served for 22 years in active-duty service, according to his website, including a stint in the Gulf War in 1991. He said he was later assigned to a White House communications job, penning a book about his experience, before retiring from the service in 2001. He then spent more than 10 years with the State Defense Force, rising to become its commanding general.

During his time as the unit’s brigadier general, Gelhardt led about 500 other unpaid volunteers, including some who are retired U.S. service members. Created by state law, the force assists the state National Guard and the Department of Defense.

Over the years, its work has helped state authorities respond to the coronavirus pandemic by working at food banks and COVID-19 vaccination sites.

Gelhardt, who indicated on his website that he had political aspirations, also speaks often at military gatherings. He spoke at a Memorial Day event at the Marietta National Cemetery in June, shortly before he resigned, urging the crowd to remember those who lost their lives in service to their country.

“I challenge each and every one of you to take today and be the best free American citizen you can be,” he said. “And tomorrow, do it again.”